Concrete is used to construct a variety of structures, such as building walls and floors, bridge supports, dams, columns, raised platforms and the like. Typically, concrete structures are formed using embedded reinforcement bars (often referred to as rebar) or similar steel reinforcement material, which provides the resultant structure with increased strength. Over time, corrosion of the embedded reinforcement material can impair the integrity of the embedded reinforcement material, the surrounding concrete and the overall structure. Similar degradation of structural integrity can occur with or without corrosion over sufficiently long periods of time, in structures subject to large forces, in structures deployed in harsh environments, in structures coming into contact with destructive materials or the like.
FIGS. 1A, 1B and 1C show a number of partial cross-sectional views of an exemplary damaged structure 10. Structure 10 includes a first portion (e.g. a wall) 12 having a surface 14 that is damaged in regions 16A, 16B, 16C. In the illustrated example of FIGS. 1A and 1B, damaged regions 16A, 16B, 16C represent regions where surface 14 is indented—i.e. the damage to structure 10 has changed the cross-sectional shape of portion 12 in damaged regions 16A, 16B, 16C.
There is a desire for methods and apparatus for repairing and/or restoring existing structures which have been degraded or which are otherwise in need of repair and/or restoration.
Exemplary structure 10 also includes portions 18A, 18B on opposing sides of portion 12. In the case where portion 12 is a wall, portions 18A, 18B may represent a floor and ceiling, for example. Portions 18A, 18B of structure 10 respectively form inside corners 20A, 20B with portion 12. Portions 18A, 18B constrain the ability to work in a vicinity of portion 12 and, in particular, in a vicinity of surface 14 which is in need of repair and/or restoration. For example, it may not be possible to access surface 14 of portion 12 by moving in one or more directions parallel with surface 14 from one side of portion 18A (or 18B) to the opposing side of portion 18A (or 18B). Instead, it may be necessary or desirable to access surface 14 from a direction normal to surface 14 (e.g. in direction 22 (FIG. 1A).
There is a general desire to repair and/or restore existing structures wherein there are constraints on the ability to access the portion(s) and/or surface(s) of the existing structures.
Constraints on access to existing structures (and/or portion(s) and/or surface(s) thereof) in need of repair and/or restoration are not limited to constraints imposed by other portions of the same structure, as is the case of exemplary structure 10 of FIGS. 1A, 1B and 1C. Access to existing structures may be limited by other constraints, such as, by way of non-limiting example, the ground, a body of water, other structures and/or the like.
Some structures have been fabricated with inferior or sub-standard structural integrity. By way of non-limiting example, some older structures may have been fabricated in accordance with seismic engineering specifications that are lower than, or otherwise lack conformity with, current seismic engineering standards. There is a desire to reinforce existing structures to upgrade their structural integrity or other aspects thereof. There is a corresponding desire to reinforce existing structures wherein there are constraints on the ability to access portion(s) and/or surface(s) of the existing structures.
There is also a desire to protect existing structures from damage which may be caused by, or related to, the environments in which the existing structures are deployed and/or the materials which come into contact with the existing structures. By way of non-limiting example, structures fabricated from metal or concrete can be damaged when they are deployed in environments that are in or near salt water or in environments where the structures are exposed to salt or other chemicals used to de-ice roads. There is a corresponding desire to protect existing structures wherein there are constraints on the ability to access portion(s) and/or surface(s) of the existing structures.
The desire to repair, restore, reinforce and/or protect existing structures is not limited to concrete structures. There are similar desires for existing structures fabricated from other materials.